16) The Larynx

Question 1

What are the functions of the larynx? (4)

Answer 1

Ventilation
Airway protection
Cough
Phonation

Question 2

Describe the location of the larynx:

Answer 2

Between hyoid bone and trachea (C4-C6)

Question 3

What are the main cartilages making up the larynx?

Answer 3

Epiglottis, thyroid, cricoid and arytenoid

Question 4

Where does the epiglottis attach?

Answer 4

Anteriorly to hyoid and inferiorly to thyroid cartilage (thryoepiglottic ligament)

Question 5

What is the function of the epiglottis?

Answer 5

Cover laryngeal inlet to prevent fluids or food entering resp. tract

Question 6

What is the vallecula and its significance?

Answer 6

Depression between tongue base and epiglottis

Important for intubation of trachea

Question 7

Describe the movements during swallowing to prevent food entering the respiratory tract:

Answer 7

Epiglottis pulled down and larynx pulled up and forward

Question 8

How does epiglottitis present?

Answer 8

Sore throat, fever, drooling, sounds on breathing

Question 9

What is the likely causative organism of epiglottitis?

Answer 9

H. influenzae

Question 10

Describe the structure of the thyroid cartilage:

Answer 10

Two laminae meeting in midline to create the laryngeal prominence

Question 11

How is the thyroid cartilage joined to the other cartilages of the larynx and nearby bone?

Answer 11

Joined to hyoid by thyrohyoid membrane

Joined to cricoid by cricothyroid ligament (membrane)

Question 12

Describe the cricoid cartilage:

Answer 12

Complete ring of cartilage, connected to trachea by cricotracheal membrane

Question 13

Describe the arytenoid cartilages and what attaches to them:

Answer 13

Sit on top of cricoid posteriorly and are points of attachment for vocal and vestibular ligaments

Question 14

What is cricoid pressure?

Answer 14

Pressing on cricoid cartilage from front to compress oesophagus and stop regurgitation

Question 15

What is a cricothryoidotomy?

Answer 15

Making an emergency airway through cricothyroid membrane

Question 16

What forms the false vocal cords?

Answer 16

Vestibular fold (ligament)

Question 17

Describe the true vocal cords:

Answer 17

Vocal fold with vocal ligament and vocalis muscles forms true vocal cord. Stratified squamous epithelium

Question 18

Where do the vocal cords attach?

Answer 18

Anteriorly - thyroid cartilage (fixed)

Posteriorly - arytenoid (mobile)

Question 19

How are the vocal cords moved?

Answer 19

Intrinsic muscles of larynx pull arytenoids causing them to pivot on cricoid cartilage and move the cords

Question 20

How would the vocal cords appear during ventilation?

Answer 20

Abducted

Question 21

How would the vocal cords appear during phonation?

Answer 21

Partially abducted

Question 22

How would the vocal cords appear during swallowing?

Answer 22

Adducted

Question 23

What is the only intrinsic muscle of the larynx to be located external to the larynx?

Answer 23

Cricothyroid

Question 24

What is the function of cricothyroid?

Answer 24

Tense the vocal cords causing higher pitch sounds

Question 25

What is the innervation to cricothyroid?

Answer 25

External branch of superior laryngeal nerve (CN X)

Question 26

What muscle causes abduction of the vocal cords?

Answer 26

Posterior cricoarytenoid

Question 27

What are some functions of the intrinsic muscles of the larynx?

Answer 27

Adduction and abduction Relaxation and tension of vocal cords Pulls epiglottis over laryngeal inlet

Question 28

What are the 3 regions of the larynx?

Answer 28

Supraglottis - epiglottis to vestibular folds Glottis - cords plus 1 cm Subglottis - to lower border of cricoid

Question 29

What does the recurrent laryngeal nerve innervate?

Answer 29

Sensory to subglottis and motor to intrinsic muscles of larynx

Question 30

What does the internal branch of the superior laryngeal nerve innervate?

Answer 30

Sensory to supraglottis

Question 31

Following thyroid surgery, a woman presents with a deep, hoarse voice. What has occurred?

Answer 31

Damage to recurrent laryngeal nerve as inferior thyroid artery runs near nerve

Question 32

What are some causes of recurrent laryngeal nerve palsy?

Answer 32

``` Thyroid disease Laryngeal cancer Thyroidectomy Apical lung tumour Aortic aneurysm ```

Question 33

How does unilateral complete injury of recurrent laryngeal nerve present?

Answer 33

Vocal cords in neutral position | Hoarseness and weaker cough

Question 34

How does bilateral injury of recurrent laryngeal nerve present?

Answer 34

Difficulty breathing Stridor Can't speak properly

Question 35

What type are the majority of laryngeal cancers?

Answer 35

Squamous cell carcinoma

Question 36

What are some risk factors for laryngeal cancer?

Answer 36

Smoking and alcohol | Male

Question 37

Why is the prognosis of cancer favourable if only the glottis is affected?

Answer 37

Minimal lymphatic drainage for glottis so less likely to spread

Question 38

What are some symptoms of laryngeal cancer?

Answer 38

``` Hoarseness Foreign body sensation in throat Dysphagia and odynophagia Otalgia (referred) Cough Weight loss ```